Engine switch with detent



Sept- 23,k 1952 L. D. BoYcE 2,611,841

ENGINE SWITCH WITH DETENT Filed May 24, 1948 F G. l

FIGB.

* INVENTOR. LEONARD D. BOYCE ATTORNEY Patented Sept. 23, 1952 ENGINE SWITCH WITH DE'IEN'I j Leonard D. Boyce, Kirkwood, Mo'., assignor to Carter Carburetor Corporation, St. Louis, Moi.,k

' a corporation of Delaware Application May 24, 194s, serial No. V28,89%

This invention relates to switch devices and consists particularly in a novel so-called kickdown control switch for use with an internal combustion engine of the automotive type.

In Patent No. 2,396,551, issued to Leonard D. Boyce," there is illustrated and claimed a switch of the above type having a stationary contact point and a movable point which can be shifted to and from its operative position responsive to suction conditions within the carburetor. A plunger is arranged to be actuated by the throttle lever upon substantially full opening of the throttle valve to close the switch contacts provided the carburetor suction is low enough to cause the movable point mentioned to be located in its operative position. The eect of closing the circuit within the switch is to cause the vehicle transmission to shift from direct drive or high gear to third gear for greater power. The transmission, as used with the patented switch, is arranged to remain in third gear until the throttle is returned to idle position.

It has been found desirable to rearrange this type of transmission so as to control the return to direct drive or high gear by opening of the kick-down switch itself. Accordingly, a kickdown switch must be provided which incorporates locking means so as to insure the holding of the switch in closed relationship and the transmission in third gear until the throttle is closed to the predetermined position at which such reshifting is desired.

The main object of the present invention is to provide such a switch.

A more detailed object is to provide a switch having a manual plunger and a pair of individually actuated elements for affecting normal switch operation by the plunger.

In the accompanying drawing:

Fig. 1 is a side View and diagram representing an automotive engine and transmission having the novel switch applied thereto.

Fig. 2 is an enlarged side View and section showing the lower portion of the carburetor and, particularly, the novel switch and actuating parts thereof.

Figs. 3 and 4 are sectional views of the switch in different positions.

The engine I is provided with the usual intake manifold I I upon which is mounted a downdraft carburetor, generally indicated at I2. The carburetor throttle is controlled by linkage I3 extending to the accelerator pedal I4 in the drivers compartment. Transmission gearing is mounted within the housing I5 located rearv 9 Claims. (Cl. ZOO-59) wardly of the engine and controlledby shifting means, in the present instance, a lever I6. HighV gear mechanism is mounted in housing I1v and provided with a kick-down, electrical control I8. A storage battery I9 is connected by wiring 20 to control I8 and throttle and suction operated switch 2I formed as a part of the carburetor and more fully illustrated in the remaining figures.

The switchy is comprised of a body 22, formed as an integral part of the carburetor'body casting, though it may be separately vformed and secured in position, and having a cross chamber 23 and intersecting vertical chambers 24 and 25.l Mounted in one wall of the body, opposite cham-` ber 23v is an insulator 26 which carries a iixedswitch point 2l and clip 28 to which is attached wiring 20. The switch body and the movable point are grounded through the carburetor and engine. .An actuating plunger 29 received longitudinally in chamber 23 has'a telescoping portion 30 at its outer extremity which slidably projects through a closure plate 3l formed on the outer wall of the switch body. Portion 3Q of the plunger is constantly urged outwardly by a coiled spring 32 in position to be engaged by an arm 33 formed rigidly on shaft 34 which mounts the throttle valve 35 within the carburetor barrel. Another, arm 35 secured to the throttle shaft has anaperture 3l for attachment of ac-f celerator linkage I3. The arrangement is such that upon substantial full opening of throttle valve 35, arm 33 engages and shifts` plunger 29-30 leftwardly. i y Y y Slidably received in upwardly extending chamber 24 is a piston 40 constantly urged downwardly by acoiled spring 4I. Chamber 24 is exposed to suction within the carburetor, anterior to throttle 35through a passage 42. On the lower extremity of piston 40, there is provided a flexible nger 43 carrying a contact forming enlargement 44 at its free end. In the normal position of piston 4U, this enlargement is positioned between plunger 29 and fixed switchA point 2l so as to be engaged by the plunger and thereby pressed against the xed switch point when the plunger is shifted inwardly by throttle lever 33. Resiliently telescoping extension 30 on the plunger limits the pressure applied to the switch point thereby.

Downwardly extending chamber 25 receives a piston 41 having an upper detent forming portion 48 which projects through an aperture 49 in a partition 50 forming the top wall of chamber Y 25 and dividing the same from chamber 23. Piston 41 is normally urged upwardly by a coiled spring 5l. in this position, detent 48 extends into chamber 23 so that, when plunger 29 and its telescoping extension 30 are urged inwardly, as in Fig. 4, to the switch closing position, the detent may slip behind an annular shoulder 52 formed on extension 30. As long as piston 41 is thus held upwardly, the plunger will be locked in its switch closing position. Fig. l4 shows a coiled spring 53 slightly compressed within extension 3U.

Extending downwardly from chamber 25 there is a suction passage 54 which opens through a port 55 (Fig. 2) into the carburetor barrel posterior to throttle 35. Throttle shaft 34 intersects this suction passage and its portion directly in line with the passage is slotted, as at 56, to form a valve. The slot is positioned so that when the throttle valve is at a predetermined position, say, from 20 to 30 degrees open or off idle, passage 54 is opened to carburetor suction posterior to the f throttle. If the engine is then in operation, the resultant suction applied to piston 4l will cause the piston and detent 48 to be drawn downwardly, thus releasing plunger 28 to be shifted outwardly by spring 53 and opening the switch points.

In;Y operation, when the carburetor throttle valve is forced wide open, and the speed of the engine is below a predetermined rate, say; 45 miles an hour, suction applied through passage 42 lto chamber 24 will be low enoughto permit piston 40 and nger 43 to shift downwardly into the path of plunger so that stationary and movable switch points 27 and 44 will be closed, thus, applying battery current to kick-down control l8 and returning the transmission gearing from high gear to third gear. At such time, the valve forming portion of throttle shaft 3,4 will close suction passage 54 so that detent 48 will be urged upwardly in position to lock plunger 29 in the switch closing position. Thereafter, the switch points will remain locked closed until the throttle returns to from 20 to 30 degrees'oilE idle (Fig. 4), whereupon suction will withdraw piston 41 and locking detent 48, releasing plunger 29 and again opening the switch.

,The invention may be modified in various 're-A spects as will occur to those skilled in the art and the exclusive use of all modifications as come within the scope of the appended claims is contemplated.

Iclaim:

l. A switch device for use with the induction conduit of an internal combustion engine comprising a pair of switch points, one vbeing movable, an actuating plunger for said movable point, a locking detent for said plunger, a uid pressure responsive element operatively connected to said detent, a suction connection for exposing said element to intake conduit suction, a valve in said connection, andlmeansto operate said valve to controlthe shifting ofgsaid detent.V

2. A switch device as described-inclaim 1 further including an additional member responsive to intake conduit suction conditions for aiecting the operation of said points by said plunger.

3. A switch device las described in claim l further including a part responsive to conduit suction conditions and operatively connected to said movable point for shifting said movable point to and from its operative position between said plunger and the other switch point.

4. A switch device for use in connection with the intake conduit of an internal combustion engine comprising a pair of switch points, one being movable, an actuating plunger for said movable point, a locking detent for said plunger, a pair of suction responsive members connected, respectively, to said movable point and said detent for shifting the same to affect switch operation, passages for exposing said members to intake conduit suction, a valve in the passage between said conduit and the suction responsive member connected ,to said detent, and manual means for controlling said plunger and said valve.

5. A switch device as described in claim 4 in which said passages extend to spaced points in the intake conduit.

6. A switch device comprising stationary` and movable contacts, an actuator for said movable contact, a vlocking element for said actuator, fluid pressure responsive means for controlling said element, a valve for controlling said pressure responsive means, and a member for operating both said switch actuator and said valve.

7. A switch device comprising stationary and movable contacts, an actuator for said movable contact, a uid pressure responsive device for shifting said movable contact to affect its operation by said actuator, alocking element for said actuator, fluid pressure responsive means for controlling said element, a valve for controlling said pressure responsive means, and a member for operating both said switch actuator and said valve.

8. A switch device for ,use in combination with the intake conduit of an internal combustion engine having a throttle comprising a pair ofv switch contacts, at least one being movable, an actuator for said movable contact, means for operating said actuator responsive to movement of said throttle, a locking element for said actuator, means responsive to pressure conditions in said intake conduit for controlling said element, and a device operable with said throttle for controlling said pressure responsive means.

9. A switch device as covered in claim l8 in which said last mentioned device comprises va valve controlling a iiuid passage connecting said pressure responsive element to saidintake manifold, said valve being operated bysaidjthrottle whereby said actuator is lockedk during a portion of the throttle movement and is lshifted during a different portion of the throttle Vznovement.,

Number Name 2,290,320 Duning July/'21,1942 2,310,755 Thumim uFeb."9, 1943 2,380,494 Ball July 31, 1945 2,396,551 U Boyce nitra'n 12, i946 

